1. Field of the Invention
The present invention relates to a method for directing an up-shift operation for a vehicle with a manual transmission, or in other words, for indicating that the vehicle is running under a condition in which an up-shifting of the manual transmission is needed.
2. Description of Background Information
For vehicles having a manual transmission, various techniques for indicating an appropriate gear position have been proposed. For instance, Japanese Patent Application laid open No. 55-31699 discloses a method in which a driving condition requiring an up-shift operation is judged by means of operating parameters of the vehicle such as the rotational speed of the engine, the opening degree of the throttle valve, and the gear position or the vehicle speed. However, other operating parameters are usually not utilized. Therefore, there can be a case that the running condition of the vehicle is judged that the up-shifting of the manual transmission is necessary although the vehicle is running on an uphill road. A direction of the up-shift operation is in turn generated in response to the judgment. In that case, if a driver of the vehicle up-shifts the gear position in accordance with the direction under that running condition, it becomes difficult to maintain the vehicle speed and an immediate down-shift operation will become necessary. therefore, it is conceivable to continuously stop generating the direction of the up-shifting when the engine load is relatively high. However, this measure is not practical because the necessary direction of up-shifting may not be generated, for example, when the vehicle is entering into an expressway through an acceleration lane. Thus, in this kind of situation, the vehicle will be prevented from entering into the operation of low fuel consumption. Therefore, an improved method for indicating up-shift operation which is free from these problems has long been required.